Twitter has suspended the account of a British journalist who tweeted the corporate email address of an NBC executive. The reporter, Guy Adams of the Independent, has been acerbic in his criticisms of NBC’s (awful) performance during the Olympics in London.

Adams has posted his correspondence with Twitter, which claims he posted a private email address. It was nothing of the kind, as many including Deadspin have pointed out. (Here’s the policy, which Adams plainly did not violate, since the NBC executive’s email address was already easily discernible on the Web — NBC has a firstname.lastname@ system for its email, and it’s a corporate address, not a personal one — and was publicly published over a year ago.)

What makes this a serious issue is that Twitter has partnered with NBC during the Olympics. And it was NBC’s complaint about Adams that led to the suspension.

Twitter has been exemplary in its handling of many issues over the past several years, including its (for a social network) brave stance in protecting user privacy. So I’m giving the service the benefit of the doubt for the moment, and hoping that this is just a foolish — if well-meaning — mistake by a single quick-triggered Twitter employee. If so, Twitter should apologize and reinstate Adams’ account immediately. If it does so, there’s little harm done — and the company will have learned a lesson.

If not, this is a defining moment for Twitter. It will have demonstrated that it can be bullied by its business partners into acts that damage its credibility and ultimately the reason so many of us use it as a platform. And if that’s the case, there will be much less incentive to use it.

If it’s a one-off, then it won’t do much harm. Let’s hope it was just a dumb lapse and someone acting on their own.

If not, well, that’s it for Twitter. No immediately, but once that kind of commercially driven censorship sets in, it’ll be game over with all the smartest users racing for the exits and a descent into myspace irrelevance.